High Heat Measured under Antarctica Could Support Substantial Life

Nearly a kilometer below the ice scientists have found a Yellowstone-like geothermal glow that could create life-rich subglacial lakes — and lubricate Antarctic ice loss

By Douglas Fox | July 10, 2015

NASA/Wikipedia Temperatures on the West Antarctic Ice Sheet can plummet below –50 degrees Celsius in winter. But under the ice scientists have found intense geothermal heat seeping up from Earth’s interior. The heat production that they measured is nearly four times the global average — “higher than 99 percent of all the measurements made on continents around the world,” says Andrew Fisher, a hydrogeologist at the University of California, Santa Cruz, who worked on the project. This excessive heat could melt up to 35 cubic kilometers of water off the bottom of the West Antarctic Ice sheet each year, according to results reported July 10 in Science Advances.

This meltwater could help create a vast, hidden habitat for aquatic life under the ice — a region that some scientists call the largest swamp on Earth. It could also influence the mechanics of the ice sheet by creating lubricated areas, which guide the flow paths and speeds of major glaciers that carry ice to the ocean. “We think that water is the knob that controls whether ice moves fast or slow,” says Slawek Tulaczyk, a glaciologist at U.C. Santa Cruz. Scientists like him need to understand that process if they are to predict just how much ice Antarctica will spill into the ocean as temperatures rise.

Researchers had already measured geothermal heat production at more than 34,000 sites around the world. But for decades, they could only make educated guesses about how much heat was seeping up under Antarctica’s ice — an area almost twice the size of Australia that had never been directly explored. That changed in January 2013 when a team co-led by Tulaczyk ventured deep into Antarctica and bored a hole through 800 meters of ice.

Tulaczyk’s team was drilling into a body of water called Subglacial Lake Whillans, which is sealed under the ice in West Antarctica — the part of the continent that sits directly south of the Pacific Ocean, between the lowermost tips of New Zealand and South America. The team hoped to see what kind of life might inhabit the lake. Their experiment also created the perfect opportunity for jabbing a giant thermometer into its bed — a metal spear, three meters long, accurate to one one-thousandth of a degree C. Fisher had spent two years building and testing the device. The critical moment came on January 31, 2013. The entire endeavor hung from a thread — or rather, a hastily knotted rope.

Geothermal night-light I accompanied Tulaczyk and a dozen other researchers to the remote drill site that year. It sat on a monotonous plain of snow and ice 600 kilometers from the South Pole. Tulaczyk blinked in the brilliant sunlight as he crawled out of his tent around 1:00 A.M. that morning. He quickly received bad news: The massive winch that he needed to lower the probe half a mile into the lake had broken down. The probe weighed 550 kilograms, more than a full-grown horse — a hefty mass that would help drive it into the subglacial mud. But now Tulaczyk and his PhD student, Kenneth Mankoff, spent eight frantic hours disassembling and redesigning it to cut its weight in half so that a smaller winch could handle it.